msg-nicdsp.c

从网卡读数据

#include <stdio.h>
#include <stdlib.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/if_ether.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <signal.h>
#include <string.h>
#include <linux/if.h>
#include <linux/socket.h>
#include <linux/if_packet.h>
#include <fcntl.h>
#include <sys/msg.h>
#define JDEBUG
#include "jdebug.h"
#include "msghdr.h"

int openintf(char *);
//void cleanup(int);
int state=0;
struct etherpacket
{
    struct ethhdr   eth;
    struct iphdr    ip;
    struct tcphdr   tcp;
    char	    buff[1600];		/*changed from 8192 by jack on Jul 18,2008*/
}ep,ep_eth0, ep_eth1;

struct iphdr	*ip, *ip_eth0;
struct tcphdr	*tcp, *tcp_eth0;
int		s;
FILE		*fp;

#define	TCPLOG	    "tcp.log"
#define INTERFACE   "eth1" 

int openintf(char *d)
{
    int fd;
    struct ifreq ifr;
    int ss;
	struct packet_mreq mr;
	struct sockaddr_ll src;
//    fd = socket(AF_INET, SOCK_PACKET, htons(0x800));
	fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_IP));
  	if (fd < 0)
    {
	perror("cant get SOCK_PACKET socket");
	exit(0);
    }
	memset(&ifr, 0, sizeof(ifr));
    strcpy(ifr.ifr_name,d);
    ss = ioctl(fd, SIOCGIFINDEX, &ifr);
    if (ss < 0)
    {
		close(fd);
		perror("cant get index");
		exit(0);
    }
	
	memset(&src, 0, sizeof(src));
	src.sll_family		= AF_PACKET;
	src.sll_protocol	= htons(ETH_P_ALL);
	src.sll_ifindex		= ifr.ifr_ifindex;
	ss = bind(fd, (struct sockaddr*)&src, sizeof(src));
	if (ss < 0)
	{
		close(fd);
		perror("cant bind eth1");
		exit(0);
	}

/*	Method 1: use setsockopt to set promiscuous mode */
	memset(&mr, 0, sizeof(mr));
	mr.mr_ifindex = ifr.ifr_ifindex;
	mr.mr_type = PACKET_MR_PROMISC;                       //bt
	ss = setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mr, sizeof(mr));
/*  Method 2: use ioctl to set promiscuous mode */
//    ifr.ifr_flags |= IFF_PROMISC;
//    ss = ioctl(fd, SIOCSIFFLAGS, &ifr);
    if (ss < 0)
	{
		perror("cant set promiscuous mode");
    	exit(1);
	}
	return fd;
}

// on May 8th
// remove read_tcp(), filter(),print_header, print_data
// print_iphdr(), print_tcphdr()

void i2a(char *data, char *str)
{
	if (data == NULL || str == NULL)
	{
		printf("error pointer\n");
		exit(1);
	}
	sprintf(str,"%d.%d.%d.%d", data[0], data[1], data[2], data[3]);
	
	return;
}

int openfifo(char *file,mode_t mode)
{
    int retv;
    retv = open(file, mode);
    if (retv < 0)
    {
        printf("cant open fifo:%s\n",file);
        exit(0);
    }
    return retv;
}

int openqueue(key_t key)
{
	int retv;
	retv = msgget(key,IPC_CREAT|IPC_EXCL);
	if (retv < 0)
	{
		printf("can not open msg queue(key%d)\n",key);
		exit(0);
	}
	return retv;
}
	

main(int argc, char *argv[])
{
	int frame_index,read_len;
	int fdin,fdout;
	msg_t omsg, imsg;
	int result, iplength;
	int eth0_read_len, snd_msg_len;
	int tmp, retv;

    s = openintf("eth1");
    ip = (struct iphdr *)(((unsigned long)&ep.ip) - 2);
    tcp = (struct tcphdr *)(((unsigned long)&ep.tcp) - 2);
    ip_eth0 = (struct iphdr *)(((unsigned long)&ep_eth0.ip) - 2);
    tcp_eth0 = (struct tcphdr *)(((unsigned long)&ep_eth0.tcp) - 2);
	fp = stdout;
	
	fdout = openqueue(NICIKEY);
	fdin  = openqueue(NICOKEY);

/*	sockwrt = openfifo(DSPFILE,);
	if (sockwrt < 0)
	{
		fprintf(stderr,"cant open dsp file:%s\n",DSPFILE);
		exit(0);
	}
*/	
	if (fork() == 0)
	{
		printf("get ready!\n");
		while (1) 
		{
			
			printf("--------get ready to read eth1------\n");
			//state=1;
			read_len = read(s, &ep_eth0, sizeof(ep));
			//state=0;
			printf("---read eth1 return: %d\n",read_len);
			memset(&omsg, 0 , sizeof(omsg));
			omsg.type = 0x1111;
			memcpy(omsg.data+5,&ep_eth0,read_len);	/*reserved some buff */
			snd_msg_len = LONGSIZE + 5 + read_len;
			//usleep(100000);                          //by bt
			tmp = msgsnd(fdout,&omsg,snd_msg_len,IPC_NOWAIT);
			if (!tmp)
			Jdebug("---write NIC IN queue %d.\n",snd_msg_len);
			else
			Jdebug("####write NIC In queue wrong.\n");
		}
	}
	else {
	while(1)
	{
		eth0_read_len = msgrcv(fdin,&imsg,sizeof(imsg),0,0);
		
		printf("read Nic OUT return:%d\n",eth0_read_len);
		eth0_read_len = eth0_read_len - LONGSIZE - 5;
		memset(&ep_eth1, 0, sizeof(ep_eth1));
		memcpy(&ep_eth1, imsg.data+5, eth0_read_len);
//		retv = write(s,imsg.data+5,eth0_read_len);
			retv = write(s,&ep_eth1, eth0_read_len-4);
		Jdebug("write eth1 return:%d\n", retv);
	}
	}
}